Becca,
Yes I really felt it around the time Flora turned 2. It was the 1st anniversary of her arrival home.
She was soooo tiny at one year, the same size our bio son was at 3 months! Of course, she grew physically and caught up mentally, it was a blur...I felt as if I was almost teased with a "baby" who was really a toddler! (14lbs/3-6 month clothes..sparse hair...sort of toddling...not really able to crawl...BUT she'd stack cups into towers, endlessly pour water from cup to cup in the bathtub, she could eat with a spoon...it was VERY confusing for my brain!)
We celebrated her 3rd birthday this fall and the "something is missing" feeling wasn't there at all.
We look at her pictures on the wall each night before we go to bed, five of them are since she's been home...the other is when she's about 6 months old and still in Guatemala. We always say "I want my baby, I want my baby" when we get to that picture. Gradually we've added to the story about how long we waited to get her and how much her brother wanted her home too. I think it will go a long way for the questions that will arrise in the future. When we used our camcorder during our year wait, we always noted the date, what else we were doing that day, where Flora's file was, if we had gotten new pictures..etc. Then, when she is a bit older and we're looking at homemovies, she'll realize that missing her was really a HUGE part of our lives.